Method for operating cupola shaft furnaces



Patented Feb. 14, 1939 UNITED STATES.

PATENT ortes METHOD FOR OPERATING CUPOLA SHAFT FURNACES Johannes Wilberz, Hilden, Germany, assignor to Deutsche Eisenwerke Aktiengesellschaft, Mulheim-on-the-ltuhr, Germany, a body corporate so Drawing. Application June 22, 1938, Serial No. 215,235. In Germany June 23. 1937 8 Claims. (01. 15-43) In the operation of cupola shaft furnaces a very great objection is, that the first iron charge charged on to the coke crushes the coke to a relatively great extent owing to its weight and as it falls from a relatively great height. This objection becomes disastrous when the heating coke itself is relatively brittle and when the furnace is of large diameter in which the weight of the iron charge is great. The filling coke disintegrated into relatively small-lumps does not develop sufficient heat to bring the first iron charge to the required temperature so that the first tapping, owing to its low running temperature often cannot be cast intouseful castings.

For the operation of cupola shaft furnaces with inferior coke of slight strength it has already been proposed to introduce the coke in largest possible lumps and to crush the coke lumps as little as possible by charging the iron charge into two or three batches. v

These measures are by no means suflicient to prevent crushing of the heating coke, especially in large size furnaces in which the first iron charge drops onto the heating cokefrom a considerable height.

In endeavoring to provide some effective remedy a buffer, preferably of chips, wool or other yieldable or resilient material is introduced according to the invention between the heating coke and the iron charge to be charged thereon.

The preferably yieldable or resilient buffer piled to a suitable height on the coke deadens the shock during the charging of the first iron charge so that the heating coke is protected in an excellentmanneragainst disintegration.

Wood shavings, wood wool, mineral wool or other combustible or fusible substances can be used as yieldable buffer.

A particularly advantageous and favourable mode of a carrying out the invention consists in using'as yieldable buffer iron shavings, especially steel wool or similar large surfaced and small sectional iron poor in carbon as addition of steel increases the, temperature of the molten charge.

Such a resilient buffer of bulky steel shavings, steel wool or the like vremains'hanging in the shaft of the furnace when it is introduced and descends relatively slowly under the weight of the first iron charge, thereby resiliently deadening the effect of the falling iron charge.

In cases, when additional quantities of heating coke are, introduced for supplementing the heating coke burned in the course of the furnace operation, it-is also advisable according to the invention to place a yieldable bufler, preferably of steel shavings or steel wool on this additional quantity of heating coke in order to keep th'coke in as large lumps as possible.

I claim:- 7 1. Method for operating cupola shaft furnaces consisting in introducing a buffer of 'yieldable,. resilient material between the heating coke and the iron charge to be charged thereon.

2. A method as specified in claim 1, in which shavings are used as bufl'er.

3. A method as specified inclaimr 1, in which mineral wool is used as buffer.

4. A method as specified in claim 1, in which the buffer consists of combustible material.

5..A method as specified in claim 1, in which 25 the bufier consists of fusible material.

6. A method as. specified in claim 1, in which wood shavings are used as bufler.

7. A method as specified in claim 1, in which the bufler consists of large surfaced small crosssectional iron poor in carbon.

8. A method as specified in claim 1, in which the buffer consists of steel wool.

JOHANNES WILZBERZ- 

